peer2peergames

Reversi

Reversi, not Othello, and the difference is the opening: the board starts empty and the players put the first four discs down themselves. That is the 1883 game. Everything after those four is the Reversi everybody knows.

Play Reversi Leaderboard

The rules

  1. The board starts EMPTY. The first four moves place one disc each on the four centre squares, alternating, and these turn nothing: they are the opening, not captures.
  2. After those four, every move must outflank: place a disc so that a line of your opponent's discs sits between it and another of yours, with no gaps.
  3. Every disc you outflank turns to your colour, in every direction at once. You do not get to choose which, and you do not get to turn fewer.
  4. A line can run along a row, up a column, or on either diagonal, and one move can trap lines in several directions at the same time.
  5. A move that outflanks nothing is not a move. If a square is not marked, it cannot be played.

When you cannot move

  1. If you have no legal move, your turn is forfeited and your opponent plays again. This is a rule, not a fault, and the page says when it happens.
  2. You cannot give up a turn you could have played. If a move is available to you, you must make one.

How a game ends

  1. When NEITHER side can move, the game is over. That can happen with the board not full, and it is not a bug when it does.
  2. Whoever has more discs at the end wins.
  3. If the game ends before the board is full, the empty squares are counted for the winner, so every final score adds up to 64.
  4. An equal game is a tie, and is recorded as 32 to 32 whatever was on the board.
  5. A game also ends if somebody resigns, or if a move deadline passes without a move: the deadline is set when the game is made, and running out of time loses it.

Worth knowing before you start

  1. The four corners can never be turned. Nothing can outflank a corner, because there is no square on the far side of it, so a corner is yours for the rest of the game.
  2. Which is why the squares NEXT to an empty corner are the dangerous ones: playing there is usually what hands the corner over.
  3. Having more discs in the middle of a game means very little. Games magazine put it well in 1982: the best strategy is usually to limit your opponent's options by turning as FEW discs as possible for the first two thirds.

Othello is a registered trademark; Reversi is the older game it was built from, and the free-placement opening above is what makes this one Reversi rather than a copy of the other.

Playing it here

  • Against a person or the bot. The bot needs no account and starts at once. To play a person, be rated and keep your games, you need an account: an email address and a password.
  • At your own pace. Every move has a deadline you both see, from five minutes to a week. A game can take an evening or it can take a fortnight.
  • Nothing to buy and nothing to win. No stakes, no prizes, no boosts, no undo. The only thing on offer is a place on a leaderboard, and only if you want one.
  • Every game can be checked. Anything decided by chance comes from the game's seed, and the seed is published the moment the game ends, so any finished game can be replayed and verified by anyone. See fair play.